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Now that we have messed up the deck, we need a way to put it back in order. Ironically, there is an algorithm for sorting that is very similar to the algorithm for shuffling. This algorithm is sometimes called selection sort because it works by traversing the array repeatedly and selecting the lowest remaining card each time.

During the first iteration we find the lowest card and swap it with the card in the 0th position. During the ith, we find the lowest card to the right of i and swap it with the ith card.

Here is pseudocode for selection sort:

    for (int i=0; i<; i++) {
      // find the lowest card at or to the right of i
      // swap the ith card and the lowest card

Again, the pseudocode helps with the design of the helper methods. In this case we can use swapCards again, so we only need one new one, called findLowestCard, that takes an array of cards and an index where it should start looking.

Once again, I am going to leave the implementation up to the reader.

Last Update: 2011-01-24